Approximately 10 million grills are sold annually in the United States. Almost all of these are either gas or charcoal. Less than 3% are electric. The drawback of electric grills heretofore has been limited maximum heating capacity set by standard load limits to household electrical circuits of 15 amperes. Although there are some higher current circuits in newer construction, for safety reasons, manufacturers and/or safety regulators, such as like Underwriter's Laboratories, limit the power draw to 1800 watts.
Charcoal grills have a number of drawbacks. They use dirty charcoal, are difficult to light, take a long time to reach optimal temperature and are messy to clean.
Gas grills do not suffer from any of the foregoing drawbacks of the charcoal grills and are gaining in popularity. They can easily produce an equivalent of over 3600 watts of heat. However, gas grills can be dangerous if not handled properly. In fact, gas grills cause more than 5000 burning or explosion accidents each year. Furthermore, they cannot be used on apartment or multi-family balconies, and one should not store them in an enclosed area like a garage, basement or enclosed porch. The gas used is highly pressurized and is potentially dangerous.
One approach to providing higher power to heating and other such portable appliances is to connect two separate circuits together such as taught in the patents of Charles (U.S. Pat. Nos. 5,302,857 and 5,160,852); Dempsey (U.S. Pat. No. 3,582,669); and Ross (U.S. Pat. No. 3,991,320) each incorporated herein by reference.
Another approach using separate elements to provide different levels of heating in a heater is taught by among others Higgins in U.S. Pat. No. 5,171,973. Higgins uses both 120 volt and 240 volt circuits to accomplish his goal of providing users with a variety of levels of heating. He also suggests use of an infra-red lamp as one of the heating elements, although he acknowledges the additional cost factor in doing so.
There are a number of electric grills of varying designs. An example of a conventional electric grill is in U.S. Pat. No. 5,524,528, Jun. 11, 1996, Class 99/446 issued to Y. Yeh incorporated herein by reference. The principal features claimed are a plurality of strips formed to define oil-leading channels and vent holes on the side wall of the seat of the griller.
These and other approaches do not offer the same advantages as the present invention.